Conventionally, liquid food such as milk or soft drink is sold in a form such that the liquid food is contained in a brick-shaped or polyhedral packaging container formed of a packaging material. In order to enable portionwise discharge of liquid food, there is provided a cap-type packaging container whose container body has a cap that can be opened and closed freely.
In this case, a packaging container manufacturing apparatus is designed to include a charging machine and a cap applicator. In the charging machine, a packaging material is formed into a container body, and a liquid food is charged into the container body. Subsequently, the container body is transported to the cap applicator by means of a conveyer. At the cap applicator, a cap is attached to the container body by any of various application methods, such as a hot melt method, a heat sealing method, or an ultrasonic sealing method.
Meanwhile, in the case of a pull-tab-type packaging container which contains liquid food in such an amount that a person can drink the food as a single serving, a discharge opening is formed in a top wall and is covered with a pull tab.
FIG. 1 is a perspective view of a conventional pull-tab-type packaging container.
In FIG. 1, reference numeral 210 denotes a container body for accommodating a liquid food; 212 denotes a top wall of the container body 210; 219 denotes a rear wall of the container body 210; and 220 denotes a side wall of the container body 210. A discharge opening 221 in the form of a punched hole is formed in a discharge opening portion defined at a predetermined position on the top wall 212, and the discharge opening 221 is covered with a pull tab 215. In this case, a person who wishes to drink the liquid food; i.e., a drinker, peels the pull tab 215 off the container body 210; removes a straw 218 from a straw package 216 bonded to the rear wall 219; and inserts the straw 218 into the discharge opening 221 in order to drink the liquid food. Alternatively, the drinker can drink the liquid food directly from the opened discharge opening 221 while placing his/her lips on the discharge opening 221.
The pull tab 215 has a horizontal portion 223 and a vertical portion 224. The horizontal portion 223 has an area greater than that of the discharge opening 221, and upon attachment to the packaging material 211 the horizontal portion 223 extends along the top wall 212 and covers the vicinity of the discharge opening 221 to thereby prevent the vicinity from being dirtied. The vertical portion 224 extends along the side wall 220 and serves as a tab used for peeling off the pull tab 215.
However, in the case of the conventional cap-type packaging container, since a cap is attached to a container body transported by means of a conveyer, the container body must be properly positioned in order to enable accurate attachment of the cap onto the container body at a predetermined position.
Accordingly, the container body must be stopped on the conveyer, or the container body must be temporarily removed from the conveyer and returned onto the conveyer after attachment of the cap. Therefore, the position at which the cap is attached varies, resulting in a decrease in quality of the packaging container. Any attempt to eliminate such variation in the cap attachment position makes the structure of the packaging container manufacturing apparatus complicated and increases the cost of the packaging container manufacturing apparatus.
The pull-tab-type packaging container has a drawback in that when a drinker places his/her lips on the discharge opening 221 in an opened state to thereby drink liquid food directly from the discharge opening 221, the drinker receives an unpleasant sensation from portions around the discharge opening 221.
An object of the present invention is to solve the problems involved in the above-described conventional cap-type packaging container and to provide a packaging container which is of improved quality and can simplify the structure of a packaging container manufacturing apparatus while reducing the cost thereof, as well as a method of manufacturing the packaging container.
Another object of the present invention is to solve the problems involved in the above-described conventional pull-tab-type packaging container and to provide a packaging container which provides a drinker with a pleasant sensation upon placement of his/her lips on portions around a discharge opening, as well as a method of manufacturing the packaging container.